Magnesium fluoborate as cellulosecarbamate reaction catalyst



United States Patent Ofifice 3,369,858 Patented Feb. 20, 1968 3,369,858 MAGNESIUM FLUOBORATE AS CELLULOSE- CARBAMATE REACTION CATALYST George H. Lonrigan, New City, and Carol A. Dupraz,

Corona, N.Y., assignors to Union Carbide Corporation,

a corporation of New York No Drawing. Filed Sept. 30, 1966, Ser. No. 583,462

12 Claims. (Cl. 8116.3)

This invention relates to the preparation of textile fabrics having improved wrinkle and shrink resistance and other improved properties. More particularly, this invention relates to the treatment of cellulosic textile fabrics with carbamate finishing agents and specifically to the use of magnesium fiuoborate as a curing catalyst in such treatment.

It is known to treat cellulosic textile fabrics with finishing agents prepared by reacting formaldehyde with aliphatic rnonocarbamates. The methylolated carbamates produced in this manner are highly effective in imparting wrinkle resistance and wash-wear properties to the fabric and also provide excellent resistance to chlorine damage and durability under conditions promoting acid hydrolysis, such as acid souring. Carbamate finishing agents have been prepared in the past from alkyl carbamates, such as methyl, ethyl propyl or butyl carbamate, as is disclosed in United States Patent No. 3,144,299, and from hydroxyalkyl carbamates, such as hydroxyethyl or hydroxypropyl carbamate. They may also be prepared from alkoxyalkyl carbamates as is disclosed in copending patent application Ser. No. 527,772, filed Feb. 16, 1966, which is of common assignee with the present application.

The carbamate finishing agents are ordinarily applied to the cellulosic textile fabric from aqueous solution utilizing conventional dipping or padding techniques. Following application to the fabric, curing is required to promote reaction with the fibers of the fabric and thereby impart the desired properties, such as wrinkle resistance and wash-wear characteristics. Use of a catalyst to promote curing is necessary and the catalysts which are known to the art to be most effective for this purpose are hydrated magnesium chloride and hydrated zinc nitrate. Curing conditions ordinarily utilized with these catalysts are curing times of about 1 to about minutes and curing temperatures of about 275 F. to about 35 0 F.

It is an object of this invention to provide an improved curing catalyst for the treatment of cellulosic textile fabrics with carbamate finishing agents. A further object of this invention is to provide a curing catalyst which is fast acting. A still further object is to provide a curing catalyst which is effective at low curing temperatures. Yet another object of this invention is to provide a superior curing catalyst which reduces the time and/ or temperature needed to adequately cure a carbamate finishing agent Without exhibiting detrimental effects on other properties. These and other objects and advantages of the invention will become apparent to those skilled in the art upon consideration of the disclosure and working examples which follow.

In accordance with this invention, it has now been discovered that magnesium fluoborate is a superior curing catalyst for the treatment of cellulosic textile fabrics with carbamate finishing agents. More specifically, it has been found that magnesium fiuoborate will promote the curing of carbamate finishing agents at markedly lower temperatures and in much shorter times than catalysts heretofore known for this use. By accelerating the reaction with the fabric, use of magnesium fiuoborate permits fabric finishers to operate their finishing ranges at a much faster speed and also minimizes problems resulting from migration by effecting reaction before the finishing agent can migrate to the surfaces of the fabric. By reducing temperatures necessary for curing, substantial economies in the finishing operation are made possible.

Carbamate finishing agents for which magnesium fluoborate serves as superior curing catalyst are products of the reaction of formaldehyde with an aliphatic monocarbamate. The useful aliphatic monocanbamates are compounds selected from the group consisting of alkyl carbamates of the general formulai 0 R0( 3NHr wherein R is an alkyl group of 1 to 4 carbon atoms, such as methyl carbamate, ethyl carbamate, n-propyl carbamate, isobutyl carbamate, and the like; hydroxyalkyl carbamates of the general formula:

H0R0- i-NH wherein R is an alkylene radical of 2 to 4 carbon atoms, such as hydroxyethyl carbamate, hydroxypropyl carbamate, and the like; and alkoxyalkyl carbamates of the general formula:

wherein R" is an alkyl group of 1 to 8 carbon atoms, R is an alkylene radical of 2 to 3 carbon atoms, and n is an integer having a value of from 1 to 10, such as methoxyethyl carbamate, ethoxyethyl carbamate, nbutoxyethyl carbamate, iso-butoxyethyl carbamate, methoxyethoxyethyl carbamate, methoxyethoxyethoxyethyl carbamate, methoxyisopropyl carbamate, methoxypropoxypropyl carbamate, isobutoxyethoxyethyl carbamate, and the like.

Methods of preparing the alkyl and hydroxyalkyl carbamates described above are well known. The alkoxyalkyl carbamates described may be readily prepared by reaction of urea with a glycol ether of the formula:

Where R", R'" and n are as defined above.

The methylolated carbamates employed as finishing agents in the process to which this invention applies are produced by reaction of formaldehyde with the abovedescribed aliphatic monocarbamates. The exact structure of the reaction product has not been established, but it is believed that a mixture of monomethylol and dimethylol derivatives is produced. The conditions under which the methylolations are carried out are not narrowly critical, with optimum conditions being determined primarily by the particular carbamate utilzed. The reaction may be effected at temperatures of from about 20 C. to the reflux temperature of the reaction mixture, with reaction times of from several minutes to as much'as 24 hours, and preferably from about 1 to about 5 hours. The formaldehyde is suitably reacted with the aliphatic monocarbamate in a ratio of from about 1.5 to about 3 moles of formaldehyde per mole of carbamate, the optimum amount depending on the particular carbamate employed. Initial pH of the reaction mixture may be in the range from about 4 to about 11, with the optimum level depending on the carbamate involved. For example, with the alkoxyalkyl carbamates the initial pH is preferably from about 8 to about 10.

The methylolated carbamates are of utility as finishing agents for cellulosic textile fabrics. As employed herein, and in the appended claims, the term cellulosic textile fabric is intended to include fabrics, whether woven or knitted, and garments or other articles made from such fabrics, and is also intended to include both cellulose fabrics, including regenerated cellulose, and cellulosecontaining fabrics. The cellulosic textile fabrics comprehended thus include cotton fabrics, linen fabrics, rayon fabrics, fabrics consisting of blends of cotton, linen or rayon fibers, andfabrics consisting of blends of cellulosic fibers and non-cellulosic fibers.

The carbamate finishing agents may be applied to the cellulosic textile fabric in any suitable manner known to the art, for example, by dipping or padding, and will ordinarily be applied from aqueous solution. If desired, the aqueous treating solution may contain, in addition to the carbamate finishing agent, other materials employed in textile finishing such as plasticizers, softening agents, hand builders, and the like.

The amount of finishing agent which is applied to the fabric will depend upon the type of fabric and its intended application, but will ordinarily be from about 1 to about 30 percent by weight, based on the weight of the textile fabric, i.e. an add-on of about 1 to about 30 percent. Preferably, the amount of finishing agent will be at least about 4 percent by weight. The add-on is, of course, determined by the concentration of finishing agent in the treating solution and the weight of solution which the textile fabric will retain, i.e. the wet pick-up. In practice, the wet pick-up may be in the range of from about 50 to about 120 percent and the treating solution applied to the textile fabric may contain from as little as about 2 percent, or less, to as much as about 25 percent, or more, of the carbamate finishing agent.

Following application of the finishing agent to the textile fabric, curing is required to promote reaction with the fibers of the fabric and thereby impart the desired crease resistance and wash-wear characteristics. Typically, the fabric is first dried, i.e. subjected to low temperature heating to remove the water, and then cured by the application of further heat. Utilizing the known curing catalysts, i.e. hydrated magnesium chloride or hydrated zinc nitrate, curing requires temperatures of at least about 275 F., and typically in the range of about 300 F. to about 350 F., and a period of at least about 1 minute, and typically in the range from about 1.5 to about 3 minutes. By employing magnesium fluoborate as curing catalyst, in accordance with this invention, curing may be effected at temperatures of as low as about 200 F., or less, and in times of as little as about 20 seconds, or less. Curing conditions may be chosen such as to provide the lowest feasible operating temperature with a relatively longer time, e.g. a temperature of 200 F. and a time of 3 minutes, or to provide the shortest feasible curing time with a relatively higher temperature, e.g. a curing time of 30 seconds with a temperature of 300 F., or to simultaneously achieve both lower temperatures and shorter times than have been possible heretofore, e.g. a temperature of 250 F. with a time of 50 seconds.

Magnesium fluoborate may be utilized as a curing catalyst in accordance with this invention in any catalytically effective amount. Good results are obtained by addition of the magnesium fluoborate to the aqueous treating solution in an amount sufficient to give a retention of magnesium fluoborate n the fabric of about 0.1 to about 5 weight percent, based on the weight of the fabric, and more preferably from about 0.2 to about 2 weight percent. Larger amounts of catalyst, within the range specified, are preferably employed at higher add-on levels of finishing agent.

As far as is known, magnesium fluoborate is uniquely effective as a catalyst for carbamate finishing agents. As indicated above, it permits markedly lower curing temperatures and/ or reduced curing times as compared with the most effective catalysts that have been employed with carbamate finishing agents in the past. Moreover, it accomplishes these advantages without any adverse effects on fabric properties such as strength, color, or resistance to chlorine damage. Closely related compounds, such as zinc fluoborate, ammonium fluoborate, and cadmium fluoborate, do not perform in a similar manner.

Evaluation of the properties of textile fabrics treated in the manner described herein was in accordance with test procedures of the American Society for Testing Materials (ASTM) or the American Association of Textile Chemists and Colorists (AATCC). The following tests were conducted:

Dry Wrinkle Recovery-measured by AATCC Tentative Test Method 66-1959 T WashWear Rating-determined by AATCC Tentative Test Method 88A1964 T. The rating, which is indicative of the smoothness of appearance of the fabric, ranges from 1 to 5 with intermediate ratings indicated by and symbols.

Tear Strengthmeasured by ASTM Method D1424-59 (Elmendorf) Tensile Strength-measured by ASTM Method D1682 (Grab) Flex Abrasion-measured by ASTM Method D-1175- 61T (Flex) Damage Due to Retained Chlorine-deterrnined by AATCC Standard Test Method 92-1962.

Example 1 To demonstrate the ability of magnesium fluoborate to function effectively as a curing catalyst at low temperatures at which catalysts known to the art are ineffective, comparison was made of the ability of magnesium fluoborate, Mg(BF and magnesium chloride hexahydrate, MgCl -6H O, to function as curing catalysts at 200 F. The fabric employed in the test was a desized, scoured, bleached and mercerized white cotton broadcloth having a thread count of 136 x 64. The carbamate finishing agent employed was methylolated methoxyethyl carbamate, prepared by reacting 1 mole of methoxyethyl carbamate with 2.2 moles of formaldehyde at 103 C. for 2 hours at an initial pH of 10 and adjusting the pH to 7 by addition of dilute hydrochloric acid after methylolation was complete.

The fabric samples tested are designated herein by the letters A and B to facilitate comparison. Sample A was treated with a solution containing 16.0% of a 50% aqueous solution of methylolated methoxyethyl carbamate, 2.0% of a 40% aqueous solution of magnesium fluoborate, 2.2% of Fabritone PE (a commercial softener composed of emulsified polyethylene Wax and having a solids content of 30%), 0 .1% Tergitol TMN (trademark for a nonionic surfactant characterized as a trimethyl nonyl ether of polyethylene glycol), and the balance water. Sample B was treated with an otherwise identical solution containing 3.2% magnesium chloride hexahydrate in place of the magnesium fluoborate. In each case, the fabric sample was immersed in the treating solution and padded through a Butterworth Laboratory Padder using a single nip to a wet pick-up of then placed on a pin tenter frame and cured in a laboratory oven at 200 F. for 4 minutes.

The dry wrinkle recovery (warp-l-filling) of the untreated fabric was degress. Fabric sample B, cured in contact with magnesium chloride hexahydrate, had a dry wrinkle recovery of degrees indicating that substantially no cure had been achieved. Fabric sample A, cured in contact with magnesium fluoborate, had a dry wrinkle recovery of 267 degrees, evidencing a high degree of cure.

Example 2 To demonstrate the ability of magnesium fluoborate to greatly accelerate the reaction of carbamate finishing agents with cellulosic textile fabrics as compared with catalysts known to the art, tests were made utilizing short curing times with magnesium fluoborate, magnesium chloride hexahydrate, and zinc nitrate hexahydrate. In

a curing period several times this long to eifect complete curing with either of the other catalysts.

Example 3 The cotton printcloth described in Example 2 above was treated with methylolated ethyl carbamate employing both magnesium chloride hexahydrate and magnesium fluoborate as curing catalysts. In each instance, the fabric was dried for 2 hours at ambient temperature prior to curing. For convenience, the results obtained are summarized in Table II below.

TABLE II Fabric Treatments Fabric Properties Methylolated Magnesium Magnesium Curing Dry Tear Warp Damage Due Ethyl Carbamate Chloride Fluoborate Wash-Wear Wrinkle Strength Tensile To Retained (50%) Hexahydrate (percent Temper- Time Tumble Dry/ Recovery Warp/Filling Strength Chlorine (percent 0.w.f.) (percent o.w.f.) o.w.t.) attire; (min) Spin Dry (deg) (g.) (1b.) (percent loss) sample C, 0.83% of a catalyst prepared by dissolving 107.1 grams of zinc nitrate hexahydrate As evidenced by the data reported in Table II, the use of magnesium fluoborate as catalyst permits substantial reduction in the time and/or temperature necessary to ef fect curing when methylolated ethyl carba mate is employed as finishing agent.

Example 4 The cotton printcloth described in Example 2 above was treated with methylolated hydroxyethyl earbamate employing both magnesium chloride hexahydrate and magnesium fluoborate as curing catalysts. In each instance, the fabric was dried for 2 hours at ambient temperature prior to curing. For convenience, the results obtained are summarized in Table III below.

TABLE III Fabric Treatments Fabric Properties Methylolated Magnesium Magnesium Curing Dry Tear Warp Damage Due Ethyl Carbarnate Chloride Fluoborate Wash-Wear Wrinkle Strength Tensile To Retained Hexahydrate (percent Temper- Time Tumble Dry/ Recovery Warp/Filling Strength Chlorine (percent o.w.i.) (percent o.w.f.) o.w.f.) a ture (min.) Spin Dry (deg) (g.) lb. (percent loss) TABLE I As evidenced by the data reported in Table III, the use of magnesium fluoborate as catalyst permits substantial Sample A B 0 reduction in the time and/or temperature necessary to Curing Time (seconds) effect curing when methylolated hydroxyethyl carbamate is employed as finishing agent. 154 12g 13g 252 1 10 270 188 210 55 Example 5 267 208 229 gig The cotton broadcloth described in Example 1 above 268 250 253 was treated with methylolated methoxyethyl earbamate 2g; utilizing magnesium fluoborate as curing catalyst at a va- 273 207 268 riety of catalyst concentrations and curing conditions. In

each instance, a polyethylene softener was employed in an amount providing 0.5 percent on Weight of fabric and the fabric sample was dried for 2 hours at ambient temperature prior to curing. For convenience the results obtained are summarized in Table IV below.

TABLE IV Treatment Fabric Properties Methylolated Magnesium Cure Dry Wash-Wear Tear Strength Filling Flex Damage Due To Methoxyethyl Fluoborate Wrinkle Tumble/Spin Warp/Filling Tensile Abrasion Retained Carbamate (percent o.w.f.) Time, Temperature, Recovery (g) Strength (Cycles) Chlorine (percent o.w.f.) sec. F. (deg) (1b.) (percent loss) As evidenced by the data in Table IV, use of magnesium fluoborate as curing catalyst does not result in any adverse effect on fabric properties.

Example 6 To demonstrate the uniqueness of magnesium fluoborate in its ability to function effectively as a low temperature curing catalyst for carbamate finishing agents, comparison was made with other fluoborate compounds, namely, cadmium fluoborate, ammonium fluoborate and zinc fluoborate, utilizing methylolated methoxyethyl carbamate as the finishing agent. The fabric employed was that described in Example 1 and, in each instance, treating conditions were such as to provide 6.0 percent of methylolated methoxyethyl carbamate, 0.5 percent of polyethylene softener, and 0.6 percent of catalyst, based on weight of fabric. After curing at 200 F. for 4 minutes, the fabric sample contacted with magnesium fiuoborate had a dry wrinkle recovery (warp-i-filling) of 267 degrees, while the corresponding values for cadmium fluoborate, ammonium fiuoborate and zinc fluoborate were 175 degrees, 180 degrees and 204 degrees respectively, evidencing that only magnesium fluoborate is effective as a low temperature curing catalyst.

Example 7 A sample of fabric, designated herein by the letter A, consisting of a blend of 65 percent polyester and percent cotton and having a thread count of 120 X 72 was treated with methylolated methoxyethyl carbamate and cured in contact with magnesium fluoborate and a second sample of the same fabric, designated herein by the letter B, was treated with dimethylol hexahydropyrirnidone-Z and cured in contact with magnesium chloride hexahydrate. After treatment, Sample A contained 6 percent methylolated methoxyethyl carbamate, 0.4 percent polyethylene softener and 0.4 percent magnesium fluoborate, while Sample B contained 6 percent dimethylol hexahydropyn'midone-Z, 0.4 percent polyethylene softener, and 0.6 percent magnesium chloride hexahydrate. Each fabric sample was cured at a temperature of 340 F. For convenience, the results obtained at various curing times are summarized in Table V below.

TABLE V Wash-Wear Rating Tumble Dry/Spin Dry Sampel A Sample B Sample A Sample B Curing Time (Seconds) As evidenced by the data in Table V, the use of magnesium fluoborate with methylolated methoxyethyl carbamate provides somewhat better .dry wrinkle recovery and wash-Wear properties on polyester/ cotton fabric than the conventional treatment utilizing methylolated hexahydropyrimidone-Z and magnesium chloride hexahydrate.

Although the invention has been illustrated by the preceding examples, it is not to be construed as limited to the materials employed therein, but rather the invention encompasses the generic area as hereinbefore disclosed. Various changes and modifications can be made in practicing the present invention without departing from it and therefore it is intended to include in the scope of the appended claims all such modifications and variations as may be apparent to those skilled in the art from the description and illustrative examples given herein.

What is claimed is:

1. In a process for treating a cellulosic textile fabric to improve crease resistance and impart Wash and wear properties thereto by applying to said fabric a finishing agent produced by reacting formaldehyde with an aliphatic monocarbamate selected from the group consisting of alkyl carbamates of the formula:

RO- NH2 wherein R is an alkyl group of 1 to 4 carbon atoms, hydroxyalkyl carbamates of the formula:

HoR'o()NH2 wherein R is an alkylene radical of 2 to 4 carbon atoms, and alkoxyalkyl carbamates of the formula:

0 R0-(RO)n( )NH2 (wherein R" is an alkyl group of 1 to 8 carbon atoms, R' is an alkylene radical of 2 to 3 carbon atoms, and n is an integer having a value of from 1 to 10, and subsequently curing said finishing agent by the application of heat, the improvement comprising effecting said curing in contact with a catalytically effective amount of magnesium fiuoborate.

2. The process as described in claim 1 wherein curing is effected in a period of about 20 seconds to about 60 seconds.

3. The process as described in claim 1 wherein curing is effected at a temperature of about 200 F. to about 275 F.

4. The process as described in claim 1 wherein the textile fabric is a cotton fabric.

5. The process as described in claim 1 wherein the textile fabric is a blend of cotton and polyester.

6. The process as described in claim 1 wherein the magnesium fluoborate is employed in an amount of from about 0.1 to about 5 percent, based on the weight of the textile fabric.

7. The process as described in claim 1 wherein the magnesium fluoborate is employed in an amount of from about 0.2 to about 2 percent, based on the weight of the textile fabric.

8. The process as described in claim 7 wherein the formaldehyde and the aliphatic monocarbarnate are reacted in a ratio of about 1.5 to about 3 moles of formaldehyde per mole of aliphatic monocarbamate.

9. The process as described in claim 7 wherein the finishing agent is applied to the fabric in an amount of at least about 4 percent by weight, based on the weight of the textile fabric.

10. The process as described in claim 7 wherein the aliphatic monocarbamate is methoxyethyl carbamate.

11. The process as described in claim 7 wherein the aliphatic monocarbam'ate is ethyl carbamate.

10 12. The process as described in claim 7 wherein the aliphatic monocarbamate is hydroxyethyl carbamate.

References Cited UNITED STATES PATENTS 2,627,524 2/1953 Malkemas et a1. 260-482 2,850,407 9/1958 Zurawic et al 117--139.4 2,928,812 3/1960 Ernst 8116.3 X 3,144,299 8/1964 Frick et al 8116.3 3,160,469 12/1964 Vail et a1. 8116.3 3,230,030 1/1966 Moran et a1. 8-116.3

J. TRAVIS BROWN, Primary Examiner.

15 NORMAN G. TORCHIN, Examiner.

J. CANNON, Assistant Examiner. 

1. IN A PROCESS FOR TREATING A CELLULOSIC TEXTILE FABRIC TO IMPROVE CREASE RESISTANCE AND IMPART WASH AND WEAR PROPERTIES THERETO BY APPLYING TO SAID FABRIC A FINISHING AGENT PRODUCED BY REACTING FORMALDEHYDE WITH AN ALIPHATIC MONOCARBAMATE SELECTED FROM THE GROUP CONSISTING OF ALKYL CARBAMATES OF THE FORMULA: 